I'm not sure how the Tucson market is but I wasn't able to find any properties qualifying for the FHA loan program for a 4-unit property in Los Angeles because of the Self Sufficiency qualification.Now I'm looking at buying a single family home and buiding an ADU on it since there are many low downpayment, low interest loan products out there for this strategy.

As you pay down mortgages, the ROE will also decline because you are increasing equity. 

During a discussion with my mortgage broker today, she mentioned that as I start doing real estate flips, an Exposure Line will be a good financial product for me.

I couldn't find any loan products that could make this happen.Now I'm leaning towards buying a single family home in a decent area of Orange County and use it as my primary residence.

If so you may need another short term loan product to get the rehab work done.

Lima One Capital also has a rental product.

For most lenders and I think for Fannie Mae products you can't count commission in order to "qualify" for the loan, so you will need to have whatever requirements are necessary.

I would, however, recommend you talk to a lender and see if they have any products similar to the FHA.

What is one software/app/product that you wish you had?

There are two schools of thought on this, I've had plumbers (that sell the products) tell me how great moen are and how they have a lifetime warranty and how the parts are always available.